Collators for assembling a plurality of signatures into groups of collated signatures, such as books or magazines, are well known in the art. A typical collator includes a single main line drive shaft which drives a collating conveyor and feeders which feed signatures to the collating conveyor. The feeders are spaced along the collating conveyor. The main line drive shaft has a longitudinal central axis and is rotatable about its longitudinal central axis. A drive motor is connected to one end of the main line drive shaft to drive the shaft about its longitudinal central axis. The feeders are drivingly connected to the main line drive shaft. The feeders are driven with proper timing to form the books or magazines on the collating conveyor.
Some disadvantages are present when a single main line drive shaft is used to drive a number of feeders spaced along a collating conveyor. One disadvantage is that the position of the feeders cannot be raised or lowered relative to the collating conveyor to better feed signatures onto the collating conveyor. This is because there are rigid mechanical connections between the main line drive shaft and the feeders.
Another disadvantage is that a single main line drive shaft may be relatively long and, therefore, may twist enough about its longitudinal central axis to cause the feeders located a distance from the drive motor to be out of proper timing. The main line drive shaft may twist about its longitudinal central axis because the drive motor driving the shaft may be located at only one end of the shaft. Another drive motor may be connected to the other end of the main line drive shaft to also drive the shaft, but additional cost and drive complexity would be incurred.
Still another disadvantage to a collator having a single main line drive shaft is that to inhibit operation of the feeders, typically mechanical parts are engaged to stop movement of a part. This results in wear of the mechanical parts.
Still another disadvantage is that the task of adjusting a particular feeder to accommodate delivery of a different-sized signature onto the collating conveyor is rather cumbersome. Such an adjustment typically requires the feeder to be first declutched from the single main line drive shaft and then the collating conveyor to be jogged until the desired adjustment is achieved. The feeder is then reclutched to the single main line drive shaft.